<!DOCTYPE html>
<html>

<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        * {
            padding: 0;
            margin: 0;
        }

        .wrap {
            width: 500px;
            margin: 100px auto 0;
        }

        table {
            border-collapse: collapse;
            border-spacing: 0;
            border: 1px solid #c0c0c0;
            width: 500px;
        }

        th,
        td {
            border: 1px solid #d0d0d0;
            color: #404060;
            padding: 10px;
        }

        th {
            background-color: #09c;
            font: bold 16px "微软雅黑";
            color: #fff;
        }

        td {
            font: 14px "微软雅黑";
        }

        /*tbody tr {
            background-color: #f0f0f0;
        }

        tbody tr:nth-child(odd) {
            background-color: #c0c0c0;
        }

        tbody tr:nth-child(even) {
            background-color: #d0d0d0;
        }

        tbody tr:hover {
            cursor: pointer;
            background-color: #f0f0f0;
        }*/
    </style>
</head>

<body>
    <div class="wrap">
        <table>
            <thead>
                <tr>
                    <th>序号</th>
                    <th>姓名</th>
                    <th>课程</th>
                    <th>成绩</th>
                </tr>
            </thead>
            <tbody id="j_tb">
                <tr>
                    <td>
                        1
                    </td>
                    <td>柳岩</td>
                    <td>语文</td>
                    <td>100</td>

                </tr>
                <tr>
                    <td>
                        2
                    </td>
                    <td>苍老师</td>
                    <td>日语</td>
                    <td>100</td>
                </tr>
                <tr>
                    <td>
                        3
                    </td>
                    <td>凤姐</td>
                    <td>营销学</td>
                    <td>100</td>
                </tr>
                <tr>
                    <td>
                        4
                    </td>
                    <td>张飞</td>
                    <td>数学</td>
                    <td>10</td>
                </tr>
                <tr>
                    <td>
                        5
                    </td>
                    <td>小沈阳</td>
                    <td>英语</td>
                    <td>100</td>
                </tr>
                <tr>
                    <td>
                        6
                    </td>
                    <td>马户</td>
                    <td>体育</td>
                    <td>100</td>
                </tr>
            </tbody>
        </table>
    </div>
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        var j_tb = document.getElementById("j_tb");
        var trs = j_tb.children;
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            //trs[i].style.backgroundColor = "red";
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            //鼠标经过当前行 当前行高亮
            trs[i].onmouseover = function () {
                bgc = this.style.backgroundColor;
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            //鼠标离开当前行 当前行复原
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</body>

</html>